Audiocom Superclock 3 Fitting In A Teac VRDS T1 Help

[Delboy2]

Hi,
I have recently purchased a second hand Audiocom Superclock 3 v2.5 which I intend to fit in my Teac VRDS T-1
Unfortunately the clock frequency on the unit I have purchased is 11.2896 MHz - my Teac requires a clock frequency of 16.9344 MHz! Is it a matter of just changing the crystal or does other components require changing? Also does anyone have a fitting guide for this Superclock?

Cheers

[UV101]

Probably best to check with Audiocom but I've changes xtals on several clocks including a Trichord clock 4 and also in audioupgrades.co.uk C1. Both times, the vendor supplied me with a new xtal £25 from trichord and considerably less from audioupgrades!

As for fitting, you need to find the XTI (xtal in) pin on the chip thats currently fed from the std xtal. The xtal should be connected to 2 pins on the chip so its just a question of finding out which 1 of the 2 it is! If you post the chip number here, I'm sure someone will advise.

How much did you pay for the clock?

[Delboy2]

The chip is CXD2500AQ - according to the schematic I have pin 53 is XTAL1 and pin 54 is XTAL0. I need to know the XTAL0 and XTAL1 connections on the Superclock board, the +VCC and gnd are marked so that is not a problem. Only paid $16 shipped from the USA as the guy had removed it from a working machine to upgrade to a Superclock 4.

Cheers

[UV101]

OK 1st thing as you say is to change the xtal to 16.9343Mhz.

Looking at the datasheet HERE the clocking pins description is ambiguos! the description is not clear if its in relation to the chip or the oscillation circuit itself. The I/O filed contradicts the way I read the description. It probably down to less than perfect translation. Nice on Sony!

I'd guess that Pin54 described as "output of 16.9344Mhz Xtal oscillation circuit" is the clock signal into the chip. To fit the clock, you need to disconnect the xtal in the player, I'd also remove the 2 caps that form part of the original clocking circuit. 1 of the holes left be xtal removal will be connected to pin 54. You need to run the clock output of the new clock to here. The other connection on the new clock output will be to gnd. The clock will also need a supply from one of the +regulators too. I'd check with audiocom over the recommended supply voltage when you order the replacement xtal.